Poly(vinylferrocenium) (PVF+) modified electrode was developed in this study for the electrochemical sensing of DNA based on the oxidation signals of polymer, adenine and guanine. Experimental parameters, such as; polymeric film thickness, DNA immobilization time and DNA concentration were examined in order to obtain more sensitive and selective electrochemical signals. After optimization studies, DNA hybridization was investigated. 相似文献
During the last few years, the potential of s-triazine derivatives in agrochemical and medicinal properties have been subjected to investigation. s-Triazine derivatives have received great attention due to their significant antimicrobial, antibacterial, antifungal, anti-HIV, anticancer, and a wide array of other biological activities. The present study reported a method for achieving Dipodal systems formed by reaction 2,4,6-trichloro-1,3,5-triazine and 4-hydroxybenzaldehyde, 2-aminophenol. Herein, we reported the synthesis of a dialdehyde and its Schiff base as a new template. The reaction of cyanuric chloride with 1 equiv. methanol and 2 equiv. of p-hydroxybenzaldehyde gave the desired dialdehyde. The dialdehyde was then reacted with 2-aminophenolto afford the corresponding multidirectional oxy-Schiff base triazines. The structures of the compounds were identified by FT-IR,1H-NMR and elemental analysis. Their antimicrobial activities were performed by using the broth microdilution method in DMSO: Phosphate Buffered Saline (PBS) against eight bacteria strain and one yeast strain. The results of the test were compared with gentamicin. It has been determined that 2,4-Bis(2-hydroxyphenylimino-4'-formylphenoxy)-6-methoxy-1,3,5-triazine (3)Padalkar, V. S., Gupta, V. D., Phatangare, K. R., Patil, V. S., Umape, P. G., Sekar, N. J. (2014) Saudi. Chem. Soc., 18, 262–268.[Crossref], [Web of Science ®], [Google Scholar] (2DP2AF) and 2-(2-hydroxyphenylimino-4'-formylphenoxy)-4-(4'-formylphenoxy)-6-methoxy-1,3,5-triazine (2)Raval, J. P., Rai, A. R., Patel, N. H., Patel, H. V., Patel, P. S. (2009) Int. J. Chem. Tech. Res., 1, 616–620.[Google Scholar] (1DP2AF) have significant antibacterial and antifungal activity against Enterococcus faecalis and Candida albicans and these effects were close to the control antibiotic used. Ent. faecalis was the most sensitive strain against both two tested chemicals. It was determined that our chemicals have similar antifungal capacity when compared to gentamicin. 相似文献
This paper reports three current mode second order filters, each of which realizes a specific function without any external passive elements. These filters realize low-pass notch (LPN), high-pass notch (HPN) and all-pass (AP) functions. Two OPAMPs, a double output OTA and a single output OTA are employed for each circuit. The filter structures can be easily cascaded since they have high output impedances. This property is especially useful for achieving high-order filters using these LPN and HPN filters as building blocks. The presented theory is verified with macro models in SPICE simulations and, using the SPICE parameters of the layout technology, post layout simulations are carried out, with parasitics extracted from the layouts of the filter chips. 相似文献
The creep behavior of nanocellulose films and aerogels are studied in a dynamic moisture environment, which is crucial to
their performance in packaging applications. For these materials, the creep rate under cyclic humidity conditions exceeds
any constant humidity creep rate within the cycling range, a phenomenon known as mechanosorptive creep. By varying the sample
thickness and relative humidity ramp rate, it is shown that mechanosorptive creep is not significantly affected by the through-thickness
moisture gradient. It is also shown that cellulose nanofibril aerogels with high porosity display the same accelerated creep
as films. Microstructures larger than the fibril diameter thus appear to be of secondary importance to mechanosorptive creep
in nanocellulose materials, suggesting that the governing mechanism is found between molecular scales and the length-scales
of the fibril diameter. 相似文献
The flow field resulting from a transverse injection through a slot into supersonic flow is numerically simulated by solving
Favre-averaged Navier–Stokes equations with κ − ω SST turbulence model with corrections for compressibility and transition. Numerical results are compared to experimental
data in terms of surface pressure profiles, boundary layer separation location, transition location, and flow structures at
the upstream and downstream of the jet. Results show good agreement with experimental data for a wide range of pressure ratios
and transition locations are captured with acceptable accuracy. κ − ω SST model provides quite accurate results for such a complex flow field. Moreover, few experiments involving a sonic round
jet injected on a flat plate into high-speed crossflow at Mach 5 are carried out. These experiments are three-dimensional
in nature. The effect of pressure ratio on three-dimensional jet interaction dynamics is sought. Jet penetration is found
to be a non-linear function of jet to free stream momentum flux ratio. 相似文献
The metabolites of the environmental pollutant, benzo[a]pyrene (BaP) are carcinogenic and mutagenic agents. Thus, the determination of additional products (adducts) of the interaction between DNA and BaP, attracts great interest in cancer research.
In this study, the determination of interaction between BaP and calf thymus double-stranded DNA (dsDNA) was performed by using differential pulse voltammetry (DPV) and constant current chronopotentiometric stripping analysis (PSA) in connection with carbon paste electrode (CPE) or glassy carbon electrode (GCE). As a result of interaction of BaP with dsDNA, the signal obtained from the oxidation of guanine decreased and a new adduct signal at a more positive potential appeared. This new peak is attributed to the formation of an adduct from the interaction of guanine with BaP. The chemically prepared anti-7,8,9,10-tetrahydrobenzo[a]pyrene-7,8-diol-9,10-epoxide (BPDE) adduct by using iodine oxidation was analyzed and the electrochemical signal of the adduct was observed. When the dsDNA modified GCE was immersed into various concentrations of BaP solution, the oxidation peak of guanine decreased and the adduct peak increased with the increasing BaP concentration. The partition coefficient was also obtained from the peak of BaP with dsDNA. The results revealed that the formation of adducts could be determined by using electrochemical DNA biosensors, which are fast, simple and cost-effective devices. Furthermore, this study promises that the analysis of other important adducts would benefit from the introduction of electrochemical methods. 相似文献
A new dynamic permittivity expression is formulated to be used in the cavity analysis to determine the resonant frequency of an equilateral triangular microstrip patch. The proper sidelength extension expressions are given for low and high substrate permittivity cases. Better accuracy with respect to the moment method and other previous models is obtained for various structural parameters and operational modes. The proposed computation is also extended for the analysis of the two-layer structure in order to determine the air-gap tuning effect on the resonant frequency 相似文献
This article considers fully laminar flow of an incompressible viscous fluid in a uniformly porous pipe with suction and injection. An exact solution of the Navier–Stokes equations is given. The velocity filed can be expressed in a series form in terms of the modified Bessel function of the first kind of order n. The volume flux across a plane normal to the flow, the vorticity and the stress on the boundary are presented. The flow properties depend on the cross-Reynolds number, Ua/ν, where U is the suction velocity, a is the radius of the pipe and ν is the kinematic viscosity of the fluid. It is found that for large values of the cross-Reynolds number, the flow near the region of the suction shows a boundary layer character. In this region the velocity and the vorticity vary sharply. Outside the boundary layer, the velocity and the vorticity do not show an appreciable change. 相似文献
The replacement of traditional ruthenium-based photosensitizers with low-cost and abundant iron analogs is a key step for the advancement of scalable and sustainable dye-sensitized water splitting cells. In this proof-of-concept study, a pyridinium ligand coordinated pentacyanoferrate(II) chromophore is used to construct a cyanide-based CoFe extended bulk framework, in which the iron photosensitizer units are connected to cobalt water oxidation catalytic sites through cyanide linkers. The iron-sensitized photoanode exhibits exceptional stability for at least 5 h at pH 7 and features its photosensitizing ability with an incident photon-to-current conversion capacity up to 500 nm with nanosecond scale excited state lifetime. Ultrafast transient absorption and computational studies reveal that iron and cobalt sites mutually support each other for charge separation via short bridging cyanide groups and for injection to the semiconductor in our proof-of-concept photoelectrochemical device. The reorganization of the excited states due to the mixing of electronic states of metal-based orbitals subsequently tailor the electron transfer cascade during the photoelectrochemical process. This breakthrough in chromophore-catalyst assemblies will spark interest in dye-sensitization with robust bulk systems for photoconversion applications. 相似文献